Planzo bills itself as an “online planning community,” allowing you to quickly and easily share your calendar entries via simple cut and paste. It speaks the Web 2.0 lingo: AJAX, RSS, XML, etc., and promises a dead easy interface with one click event creation and drag and drop event changes.
As Pete Caputa points out, there's no shortage of Web 2.0 calendaring services - we now have EVDB, upcoming.org, Trumba and a young upstart named Kiko . All these services have their strengths, but it looks like George W Bush prefers Planzo. Heh!